Derivatives of 2-mercaptopyridine-1-oxide



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United States Patent 2,742,393 DERIVATIVES 0F Z-MERCAPTOPYRIDINEJ- OXIDE Jack Bernstein, New Brunswick, William A. Lott, Maplewood, and Kathryn A. Losee, New Brunswick, N. J., assignors to Olin Mathieson Chemical Corporation, a corporation of Virginia No Drawing. Application May 19, 1953, Serial No. 356,114 11 Claims. (Cl. 167-33) This invention relates to, and has for its object the provision of: (A) compounds of the group consisting of amine-addition and quaternary ammonium salts of acids (1) of the general formula:

wherein R has the meaning given hereinbefore, R and R each represent a lower-alkyl group, R represents a member of the classconsisting of lower-alkyl and aralkyl groups, except when R and R taken together with the nitrogen atom to which they are joined represent a saturated heterocyclic group, and when R R and R taken together with the nitrogen atom to which they are joined represent an unsaturated heterocyclic group, and R represents a member of the class consisting of higheralkyl and higher-alkenyl groups. (The alkyl and aralkyl groups may be unsubstituted or contain substituents such as hydroxy and halo.)

The compounds of this invention are active against a 'wide group of microorganisms, as indicated by the following in vitro spectrum (data on the antibacterial agent aspergillic acid being included for comparison);

TABLE I Antibacterial spectrum M. I. o. ,igl mi.

Ammonium salts of 2-mer- Organism Aspep captopyridlne-loxlde acid cetyltrlcetyldlmethyl cetyl methyl Staphylococcus aureus P209 Klebsiella pneumoniae Bacillus of Calmette and Guerim; 4

TABLE 11 Anti fungal spectrum (M. I. O. rig/ml.) Ammonium slats of 2-mercaptopyrldh1e-1-oxlde Organism Oeltyl- Oetylditrlmethyl Gem methyl Asperiaillus fumigaius 1. 6 0. 8 0.8 Asperiaillus m'ger 12 3 3 Microsporu'm cam's... 0.8 0.8 Altemtm's solam' 0. 8 Candida albica'ns-.. 12 3 1. 6 Microsporum audouim 0.. 4 0. 8 1. 6 Penicillz'um notatum. 1. 6 l. 6 1. 6 Rhodotorula 0Zutim's. 3 0.8 0. 8 Saccharomyces cerevisiae..... 0.8 0. 8 0.8 Trichophyton mentagrophutes 0.8 0. 8 0.8 Fusarium bulbipenum. 3 3 3 Ceratosto'mella ulmz' 0. 4 0. 8 0. 8

Since the compounds of this invention possess broad antibacterial and antifungal properties, they are utilizable as preservatives in a wide variety of products, as mildew-proofing agents, and for sterilization and disinfecting purposes. For example, they are useful as fungicidal plant protective agents, e. g.., against Peronospora growing on grapevine.

In addition, they are valuable chemotherapeutic agents, especially fungicides, and thus are applicable in the treatment of dermatophytosis pedisand in the control of superficial fungus infections of the skin and accessible mucous membranes.

Illustrating utilization of the compounds of this invention as chemotherapeutic agents, the cetyltrimethylammonium salt of Z-mercaptopyridine-l-oxide (for example), designated as agent in the formulations below, may beformulated and used as follows:

.A. Chemotherapeutic nose drops (to be administered intra-nasally by nebulizer, gauze pack, or drops:

Agent .Lg.. 100 Phenylephrine hydrochloride mg 2.5

Phosphatebufi'er (to about pH 7).

B. Lubricating jelly:

Carboxymethylcellulose "gm" '20 Agent mg Water, q. s -1 "gm" 1010 C. Eardrops:

Agentmg 5 Urea gm l0 Intracaine hydrochloride (fl-diethylarninoethyl p-ethoxybenzoate hydrochloride)";

gm .5 Polyethyleneglycol, q. s ml 100 D. Foot powder:

Agent ..,u.g.. 50 Starch (with 5% talc), q. s gm 1 E. Ointments:

(1) White wax gm 5 White petroleum jelly gm 64 Peanut oil (or mineral oil) gm 3'1 Agent g/gm 1001000 (2) Stearic acid; g-m 12.5 Span 65. gm 10 Tween gm 6 Antioxidant gm 0.13 Agent g/gm 1004000 Water gm 71.5

.Ihe:amine-addition salts :of the invention (II) may be prepared *by thepmethod comprising interacting an amine, preferably a higher-alkyl-amine,-with a Z-mercaptopyridine-I-oxide of the general formula:

v 1 (H t 'MUO'THHW as r. ,(whereinRh-as the meaning given hereinbeforq) 'ina-substantially dry organic solvent; and recovering the reaction product.

Thecompounds (III) of this invention may be prepared by interacting a quaternary ammonium compound (IV) of the general formula:

an alltali salt of a Cl-mercaptopyridine-l-oxide of the general formula:

' (wherein-R, R ,-R R and 'R havethe meaning; given hereinbefore),-and recOvering the -reaction product-.---

The alkali salts of the 2 -mercap topyridine-Loxide reactants includethe'alkali-metal (including ammonium) and alkaline=eanthmetal salts, inter alia,-the barium, potassium; calcium, ammonium, :or sodium salts of Z-mercaptopyridine-l-oxide; 3 -ethoxy-2-mercaptopyridine-l-oxide, 2- mercapto-3 -methoxypyridine-l-oxide; 5-bromo-2-mercaptopyridine-l-oxide, 2-mercapto-3-methy1pyridine 1-oxide,

-Z-mercapto-4-methylpyridine-l-:oxide, Z-IllfilCflPIO-S-Iflflfll- .ylpyridine-1:oxide,..2. menoaptmS-methylpyridined-oxide, 1 and Z-mercapto-6-propylpyrid-ineel-oxide. (See for example, IACS 72:4362 for preparation of substituted 2-,mer-

captopyridine-l-oxides, and application Ser. No. 330,576, filed January9, 1953.) v q In .thequ-aternary ammonium reactants (IV) of the general formula:

4 nium; cetyltriethylammoniumg--- n --butylcetyldimethylammonium; cetyl-2,3 dihydroxypropyldimethylammonium; cetyldiethyl 8 hydroxyethylammonium; octadecenyldimethylethylammonium;;cetyl1- di n propyl-(fi-hydroxyy amm um; Y cq lmethr i s d m; i -ty y piperidinium; dodecylethylpiperidinium; dodecylpyridinw cty py i ium; =Ma -0 y h x h d m octylpyridinium; octadecenylpyridinium; cetylpicolinium; benzyldimethyldodecyl-ammonium;. ben'zyldimethylpentadecylammonium; benzylcetyldimethylammonium; cetyl-ochlorobenzyldimethylammonium;, benzylcetyldiethylarm monium; benzylcetylethylpropylammonium; dedecyldimethyl-3,4-dichlorobenzylarnmon-ium; benzyldimethylole- ,ylammonium; (1 phenyldodecyl)-dimethylcinnamylammonium; dimethylethyl-9-octadecenylammonium; (p-tertoctylphenoxyethoxyethyl) trimethylammonium; (2,2,4,4- tetramethylbutylphenoxyethoxye'thyl) I} dimethylbenzylammonium; (p-tert octylphenoxyethoxyethyl)-dimethylbenzylammonium; (p tertcctylphenoxyethoxyethyl)-diethylbenzylammonium; and, (p tert-octylcresoxyethoxyethyl) -dimethylbenzylarnmonium.

Preferably, in the practice of this invention the reactant (IV) and the alkali salt of the Z-mercaptopyridine-l-oxide are interacted in a solvent for the reactants, the anion of the, former and. the cation of the latter being so chosen that the salt combination thereof is insoluble in said solvent. For example, a quaternary ammonium halide interacted with the valkali metal salt of a 2-mercaptopyridine-l oxide in a substantially dry hydroxylated organic solvent (interalia, absolute alcohol, ethylene glycol, and propylene glycol); or a quaternary ammonium sulfate in- ,teractedwith an alkaline earth-metal salt of a 2-mercaptovrid srl-oxid in. .a sub aq s iqm Alternatively, compounds of the invention having the following general formula;

- (lower sum) 7} (lower alkyl) HO-N with a 2-1i1 leaptb15yi&ine-iniiae a the with in a substantially aqueous medium, and recovering the reactionproduct. -[R, R and R have the meaning given cinnamates, sulfates, methosulfates, ethosulfates, cyanides,

ole'ates,'laurates, sec-orthophosphates, and (especially) the halides (bromides, iodides, and chlorides),

The reactants (IV) include compounds having the following cationic groups,'inter a-lia: n-hexyltrimethylarnmo- 'nium; n-octyltrimethylammonimn; dodecyltrinriethylammonium;- myristyltrimethylammonium; OCtadecyItrimethylammonium; -octadecyl-tPhydroXyethyldimethylammonium; cetyltrimethylammonium; cetyldimethylethylammohereinbeforeJ Reactant-(V) may be prepared, inter alia, by interacting the quaternary reactant (IV) in which the anion is a halogen with silver oxide; when the anion is sulfate, by treatment withan equivalent amount of barium hydroxide; or, when the anion is halide or sulfate, for erg-ample, bypassing it through a suitable anion-exchange column. v

The following examples are illustrative, but by no means limitative, of the invention.

, W EXAMPLE 1 A solution of 3.89 g. of the barium salt of 2-mercapto- .pyridine-l-oxide [prepared by interacting 2-mercaptopyridine-l-oxide (JACS 72:4362) and barium hydroxide] in 20 cc. of water is added to a solutionoff 6.65 g. cetyltrimethylammoniumsulfatein-75 cc. ofwater. Theprecipitated barium sulfate is removed by filtration, and the filtrate is freeze-dried to yield about 8 g. of the product,

the cetyltrimethylammonium salt of Z-mercaptopyridinel-oxide, M. P. 152-158 C. (with decomposition).

Using 7.85 g. cetyl-2,3-dihydroxypropyldimethylammonium sulfate or 11.82 g. cetyltriethylammonium sul- Alternative method A solution of 36.4 g. cetyltrimethylammonium bro mide in 1 liter of water is shaken for twenty-four hours with 23.1 g. silver oxide, protected from light. The solid is removed by centrifugation and the supernatant filtered. The filtrate is neutralized (pH 8.3) by the addition of 11.4 g. of Z-mercaptopyridine-l-oxide; and the resulting clear solution is freeze-dried to yield a white, non-hygroscopic solid, cethyltrimethylammonium salt of Z-mercaptopyridine-l-oxide weighing about 39 g. and melting at about 148-152" C. (This compound can be crystallized from a mixture of 50 cc. absolute alcohol and 1000 cc. hexane.)

AnaL-Calcd. for C24H46ON2S! C, 70.18; H, 11.29. Found: C, 69.95; H, 11.63.

(Alternatively, instead of using the silver oxide, an anion exchange resin is employed to remove the bromide ion from the cetyltrimethylammonium bromide, and the method continued as indicated hereinbefore.)

Using molar equivalents of 3-ethoXy-2-mercaptopyri.

dine-l-oxide or 5-bromo-Z-mercaptopyridine-l-oxide, in place of the Z-mercaptopyridine-l-oxide in this alternative method, yields the cetyltrimethylammonium salts of 3-ethoxy-2-mercaptopyridine-l-oxide and S-bromo-Z-mercaptopyridine-l-oxide, respectively.

Using 33.6 g. tetradecyltrimethylammonium bromide, in place of cetyltrimethylammonium bromide in the alternative method, yields the tetradecyltrimethylammonium salt of 2-mercaptopyridine-l-oxide.

Using 34 g. of dodecylbenzyldimethylammonium chloride, in place of cetyltrimethylammonium bromide in the alternative method, yields the dodecylbenzyldimethylammonium salt of Z-mercaptopyridine-l-oxide.

EXAMPLE 2 A solution of 2.21 g. laurylpyridinium chloride in 75 cc. of Water is added to a solution of l g. of Z-mercaptopyridine-1-oxide in 30 cc. of water containing 0.312 g. sodium hydroxide. The solution is freeze-dried, and the freeze-dried solid is suspended in 75 cc. of absolute alcohol. The sodium chloride formed is insoluble in the alcohol and is removed by centrifuging the solution. The alcohol solution of the product is concentrated to dryness under reduced pressure; and the residue is then dissolved in water and freeze-dried to yield about 2.5 g. of the product, the laurylpyridinium salt of Z-mercaptopyridine-loxide.

Anal.Calcd. C22H34ON2S-H20: C, 67.31; H, 9.22; N, 7.14. Found: C, 68.02; H, 9.38; N, 6.80.

Using 2.68 g. cetyl pyridinium chloride, in place of laurylpyridinium chloride in Example 2, yields the cetylpyridinium salt of 2-mercaptopyridine-l-oxide.

EXAMPLE 3 A solution of 4.17 g. of the barium salt of Z-mercapto- 6-methylpyridine-1-oxide (JACS 72:4362) in 25 cc. water is added to a solution of 6.65 g. cetyltrimethylammonium sulfate in 75 cc. Water. The precipitated barium sulfate is removed by filtration and the filtrate freeze-dried to yield about 8 g. of the product, the cetyltrimethylammonium salt of Z-mercapto-6-methylpyridine-l-oxide.

Alternative A solution of 36.4 g. of cetyltrimethylammonium bromide in 1 liter of Water is shaken for 24 hours with 23.1 g. silver oxide, protected from light. The solid is removed by centrifugation and the supernatant is filtered. The

filtrate is neutralized (pH 8.5) by the addition of 12.8 g. 2-mercapto-6-metl1ylpyridine-1-oxide and the resulting clear solution freeze-dried to yield about 40 g. of the white, non-hygroscopic solid product.

EXAMPLE 4 A solution of 1.27 g. of 2-mercaptopyridine-l-oxide in 3 cc. absolute alcohol is added to a solution of 2.41 g. cetylamine in 1 cc. absolute alcohol. About 25 cc. dry ether is added and, after cooling and scratching, crystallization occurs. The crystalline solid which weighs about 2.7 g. and melts at about 78-80 C. is the cetylamine salt of Z-mercaptopyridine-l-oxide. (After recrystallization from alcohol-ether, the compound melts at about 79 81 C.)

Using a molar equivalent of octylamine, in place of cetylamine in Example 4, yields the octylamine salt of Z-mercaptopyridine-l-oxide.

EXAMPLE 5 A solution of 1.27 g. of Z-mercaptopyridine-l oxide in 5 cc. absolute alcohol is added to 2.69 g. of cetyldimethylamine. About 25 cc. dry ether is added and after cooling and scratching crystallization occurs. The solid, weighing about 2 g. and melting at 6263 C. is the cetyldimethylamine salt of Z-mercaptopyridine-l-oxide. (After recrystallization from alcohol-ether, the melting point was 63-64 C.)

Using a molar equivalent of lauryldiethylamine, in place of cetyldimethylamine in Example 5, yields the lauryldiethylamine salt of 2-mercaptopyridine-l-oxide.

The invention may be variously otherwise embodied within the scope of the appended claims.

We claim: i

1. Salts of the group consisting of: amine-addition salts of the general formula (higher alkyl) wherein R and R are each members of the class consisting of hydrogen and lower-alkyl; and quaternary ammonium salts of the general formula:

wherein R and R each represent a lower-alkyl group; R represents a member of the class consisting of loweralkyl and a benzyl group, except when R and R taken together with the nitrogen atom to which they are joined represent a piperidyl group, and when R, R and R taken together with the nitrogen atom to which they are joined represent a pyridyl group; R represents a member of the class consisting of higher-alkyl and higher-alkenyl groups; and R represents a member of the class consisting of hydrogen, lower-alkyl, lower-alkoxy and halogen groups.

2. Quaternary ammonium salts of the general formula:

R: s- Ni R3 (higher alkyl) 3. (Higher alkyl)-tri lower alkyl)-arnmoniurn salts of Z-merceiptopyridine-l-oxide of the general formula:

l 4. (A benzyl)-di-(lower alkyD-(hi'gher alky1)-amrnonium salt of Z-mercagtopyridine-l-oxide.

5. cetyl-trimethyl-alnrnonium salt of Z-mercaptopyriii -l' a. a v ,'6 Laury1 pyridihium salt of z-rnercaptopyridine-lbinds. a A I 7. \ifhichiess'entially cornprises interacting .a q aterhary ammonium compound of the general formula wherein R and R each represent a lower-alkyl group, R? represents a member of the class consisting of loweralkyl and'a benzyl group, ex'tinet when R and R taken to- 'gether with the nitrogen atom to Whichthey are joined represent a piperidyl'group', and when R R and R taken together with the nitrogen atom to which they are joined represent a pyridyl g 1oup, and R represents a member of the class consistingofghigher-alkyl and higher-alkenyl groups with an alka'li'salt of a '2 rnerc'aptopyridine-l-oxide of the general formula:

wherein R r eprese'nts'a'iiierhher'of the class consisting jof 9. A fungicidalplant protective preparation comprisi ng as a fungicidal agent a salt of the class c'orisis'tingofz the'amine-additi'on salts and quaternary ammonium salts of claim 1. V

10. A fungicidal plant protective preparation for grape- :vi'necomprising as a fungicidal agent a salt of the class 'co'n'sist'ingofz 'the amine addition salts and quaternary ammonium s'altsbf claim 1. 7

1l. The method of protecting grapeyines against remno po comgrising applying a saltjof the class co'nsisting'ofz' the amine-addition and quaternary ammonium salts of claim 1.

References Cited'in the file of this 'patent 'Itai, chem; Ab'st., v01. 44,"p 4473-4 1930 

1. SALTS OF THE GROUP CONSISTING OF: AMINE-ADDITION SALTS OF THE GENERAL FORMULA 